Progress in Asymmetric Hydrogenation of Aromatic N-Heterocyclic Compounds

The structure of chiral saturated N-heterocyclic compounds widely exists in natural products, bioactive molecules, and drug molecules.Catalytic asymmetric hydrogenation of aromatic N-heterocycles is one of the most effective methods for the construction of these compounds.However, due to the strong conjugation stability of nitrogen-containing aromatic heterocyclic compounds and the poison effect of nitrogen atoms in the products on metal catalysts, the development of asymmetric hydrogenation reactions of these compounds lags far behind, and there are relatively few research reports.Therefore, how to develop efficient catalytic systems to activate the inert substrate and precisely control the stereoselectivity of the reaction is the key scientific issue of relevant research.In recent years, the development of a series of metal and organo catalysts has led to significant progress and shown broad prospects for its applications.Considering that the structures and properties of different catalysts have remarkable influence on the reactivity, selectivity, and substrate generality of the target transformations, an overview of asymmetric hydrogenation of aromatic N-heterocyclic compounds categorized is provided according to the types of catalysts.